Nine one-hundredths to john e



D. DUNN. AIR BRAKE.

(no Model.)

Patented Feb. 23, 189 7.

Inventor.

Witnesses.

AttorneyS DENNIS DUNN, OF MAHANOY CITY, PENNSYLVANIA, ASSIGNOR OF FORTY- NINE ONE-HUNDREDTHS TO JOHN E. REYBURN, OF PHILADELPHIA,

PENNSYLVANIA.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 577,425, dated February 23, 1897.

Application filed May 26, 1896. Serial No. 593,147. (No model.)

To all whom, it may concern.- Be it known that I, DENNIS DUNN, a citizen of the United States, and a resident of Mahanoy City, in the county of Schuylkill and State of Pennsylvania, have invented certain new and useful Improvements in Air-Brakes; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, which forms a part of this specification.

My invention relates to improvements in air-brakes for street-railway cars and air-compressing mechanism connected therewith; and its object is to provide an improved construction of the same whereby I secure important advantages with respect to efficiency in operation.

The invention consists in the novel construction and combination of parts hereinafter fully described and claimed.

In the accompanying drawing, the figure is a longitudinal sectional View of a portion of a car, showing my improvements applied thereto.

I11 the said drawing the reference-numeral 1 designates the bottom of an electric, cable, or other car of any ordinary or suitable construction, 2 the axles thereof,and 3 the wheels.

Fixed centrally to one of the said axles is a mutilated gear-wheel l, or one having cogs or teeth on apart of its periphery only. These cogs alternately mesh with rack-teeth 5 on the side bars 6 of a rectangular reciprocating frame 7, having horizontal rods 8 at each end, provided with coiled springs 9. To the outer end of one of said-rods is attached the piston- 10 rod of apiston 12,located in an aircompressing cylinder 13, provided at each end with airinlet valves 1 1 14, and opposite outlet-valves 15, located, respectively, in pipes 16 16 and 17 17. The pipes 17 are connected by a horizontal pipe 18, which in turn is connected with a vertical pipe 19, connected with one end of an air-cylinder 20. Located in this cylinder is a piston 21, provided with a piston-rod 22, which is connected with the brakerod 23, by which the brakes are operated. Stops 24 are provided in said cylinder for 32, which projects through and works in a slot in said valve-chamber.

The operation is as follows: When the brakes are released, the parts will occupy the position shown in the drawing. As the car is propelled the mutilated gear will alternately engage with the rack-teeth of the side bars of the rectangular frame, reciprocating the latter and the air-compressing piston connected therewith. The air from the air-compressor will escape to the air-cylinder, and from thence to the horizontal pipe 24 to the valve-chamber at the right end thereof, and from thence to pipe 25 and back to the air-cylinder, thus balancing the piston therein.

To set the brakes from the right end of the car the valve-rod is elevated, rotating the valve in chamber 29 and opening communication between pipe 24 and the pipe leading to theatmosphere. The air will now escape from the air-cylinder at the right of the piston, and the air in the opposite side expanding will force the piston to the right, setting the brakes through the medium of the connecting-rod. A reverse movement of said valve-rod will release the brakes. The coiled springs 9 will aid in reversing the movement of the rectangular frame. The brakes can be set at the opposite end of the car by operatin g the valve-rod at that end to open communication between pipe 24 and the outlet-pipe in valve-chamber 28.

For the purpose of storing up power to be used in an emergency I provide at each end of the car an air-tank 34:, communicating with valve-chambers 29 and by pipes 35.

By turning the valves in the valve-chambers until communication is established between the pipes 24 and 25 and the tanks air can be forced into said tanks and the valves then returned to normal position, confining the air in said tanks. The air in said tanks is only to be used when the air-cylinder should fail from any cause, so that if the supply should give out by operating said valves as just described the air from said tanks Will escape to the air-cylinder, so as to maintain the pressure therein. The valves are then returned to normal position, closing said tanks, when the brakes are ready to be set by the operation just described' The air-eyllnder may be provided with a re lief-valve to allow the air to escape When the desired pressure has been obtained, or means may be provided for cutting out the pump to prevent injury to the parts by overpressure, but such form no part of my present invention, and as they are Well known in the art illustration thereof is not deemed necessary.

Having thus fully described my invention, what I claim is- 1. In an air-brake, the combination with the axle, the mutilated gear, the rectangular rackframe, the rod connected therewith, the aircompressor provided with inlet and outlet valves, and the piston in said compressor, of the air-cylinder, the piston therein, the pipe connecting said compressor and cylinder, the horizontal pipes connected with said air-cylinder atopposite sides of the piston, the valvechambers at the ends of said pipes, the oscillating valves, the valve-rods, and the outletpipes; substantially as described.

2. In an air-brake the combination with the axle, the mutilated gear, the rectangular rackframe, the coiled spring, the air-compressor, provided with inlet and outlet valves, and the piston in said compressor, of the air-cylinder connected with said compressor, the piston therein, the horizontal parallel pipes connected with said air-cylinder at opposite sides of the piston, the valve-chambers at the end of said pipes, the oscillating valves, the valverods, the outlet-pipes and the storage-tanks connected With said valve-chambers; substantially as described.

In testimony that I claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.

DENNIS DUNN.

IVitnesses:

WILLIAM H. BAILEY, FRANK II. SNYDER. 

